How Bones Work

Hulton Archive/Getty ImagesA diagram showing back and side views of the human skeleton, circa 1900

The human body is an incredible machine. It runs so well most of the time that we don't have to pay much attention to any of the life-sustaining systems that are in motion around the clock, humming along without our mindful involvement.

In this article, we'll discuss one of the systems that makes life possible: the skeletal system.

Bones prevent you from puddling on the floor in the form of a jellyfish, but what else do they do? Bones rebuild themselves, they produce blood cells, they protect our brains and our organs, they provide a giant system of levers that allow us to move ourselves around, and bones also help maintain a steady amount of calcium in our bodies.

And, even if you never make your mark on the world (or in the history books), your bones will stick around long after you have otherwise vanished to declare to the world: "These skeletal remains once supported skin and tissue and organs! This person once existed!" And as the construction crew that unearthed your bones reels back in horror, every life choice you ever made will seem -- if but for a moment before you are shoveled into a Dumpster -- very much worthwhile.

Before we leave behind our skeletal remains to freak out future generations, we should first learn some basics about bones: What are bones made of? What happens when they break? And just how many of them do you have, anyway?